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How to validate an email address in PHP

...emailaddress } Additionally you can check whether the domain defines an MX record: if (!checkdnsrr($domain, 'MX')) { // domain is not valid } But this still doesn't guarantee that the mail exists. The only way to find that out is by sending a confirmation mail. Now that you have your eas...
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Python: Find in list

... the elements inside myList. Maybe you try to find a string that does not exactly match one of the items or maybe you are using a float value which suffers from inaccuracy. As for your second question: There's actually several possible ways if "finding" things in lists. Checking if something is in...
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Can't get rid of header X-Powered-By:Express

I am running a server on nodejs with express. I can't seem to get rid of the header: 13 Answers ...
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Determine if two rectangles overlap each other?

...ts from the user to construct rectangles (between 2 and 5): height, width, x-pos, y-pos. All of these rectangles will exist parallel to the x and the y axis, that is all of their edges will have slopes of 0 or infinity. ...
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Principal component analysis in Python

.... I have not had the chance to test it myself, but I've bookmarked it exactly for the PCA functionality. share | improve this answer | follow | ...
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Resetting generator object in Python

...rsion of your generator: y = FunctionWithYield() y, y_backup = tee(y) for x in y: print(x) for x in y_backup: print(x) This could be beneficial from memory usage point of view if the original iteration might not process all the items. ...
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Extracting the last n characters from a string in R

...'s straight-forward to make a function to do this using substr and nchar: x <- "some text in a string" substrRight <- function(x, n){ substr(x, nchar(x)-n+1, nchar(x)) } substrRight(x, 6) [1] "string" substrRight(x, 8) [1] "a string" This is vectorised, as @mdsumner points out. Cons...
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Group By Multiple Columns

... Use an anonymous type. Eg group x by new { x.Column1, x.Column2 } share | improve this answer | follow | ...
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Replacements for switch statement in Python?

I want to write a function in Python that returns different fixed values based on the value of an input index. 44 Answers...
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SQL is null and = null [duplicate]

...t on rows by coding where my_column = null. SQL provides the special syntax for testing if a column is null, via is null and is not null, which is a special condition to test for a null (or not a null). Here's some SQL showing a variety of conditions and and their effect as per above. create tabl...